Halogen containing polymer compounds containing modified zeolite stabilizers

ABSTRACT

The present invention relates to a halogen containing polymer compound containing a modified zeolite stabilizer. The modified zeolite stabilizer has a small particle diameter, narrow particle size distribution and less than 10 weight percent water. The modified zeolite stabilizer is formed by shock annealing, coating or a combination of the two methods.

FIELD OF INVENTION

This invention relates to halogen containing polymer compounds. Inparticular, the invention relates to halogen containing polymersstabilized by modified zeolites. The modified zeolites have a smallparticle size, narrow particle size distribution, and a reduced watercontent. When incorporated into a halogen containing compound, themodified zeolites improve the processing stability of the compound anddo not adversely diminish its physical properties. Furthermore, theinvention relates to a halogen containing polymer compound stabilized bya modified zeolite and having improved processing stability. Moreover,this invention relates to a method of forming such a halogen containingpolymer compound incorporating a modified zeolite therein.

BACKGROUND OF THE INVENTION

Halogen containing polymers tend to degrade or deteriorate whenprocessed. Generally, the difference between the processing temperatureand the degradation temperature is very small. Therefore, there is arisk that during the processing of these halogen containing polymers,that the polymer will degrade. When such polymers degrade, it isbelieved that the halide acid generated by the polymer attacks thecomponents of the processing equipment. Also, this acid furthercatalyzes elimination reactions and additional degradation of thepolymer.

Stabilizers have been developed to help deter such degradation. Forexample, organic compounds are commonly used. In some instances,zeolites have also been used as stabilizers.

Zeolites are effective acid scavengers for halogen containing polymersand enhance the thermal stability of halogen containing polymers. Acidscavengers are compounds that react with acids to form a compound thatis typically chemically inert. However, the use of zeolites asstabilizers or acid scavengers in halogen containing polymer compoundshas been limited for several reasons. First, the zeolites generally havea large particle size, generally in the range of about 3 to about 6microns. The large size of the zeolite particles not only causes surfaceblemishes on the finish of the end product made from such a polymer butalso diminishes the physical properties of such polymers. Further,outgassing occurs frequently with polymers containing zeolites when thepolymer is heated during processing due to the evolution of water fromthe zeolite during the heating. As a result, there is foaming.

U.S. Pat. No. 4,000,100 discloses a thermal and light stabilizedpolyvinyl chloride resin. The stabilizer used in the compositioncomprises an unactivated zeolite A molecular sieve or an unactivatednaturally occurring molecular sieve of essentially the same pore sizerange as zeolite A and a conventional inorganic, organometallic ororganic stabilizer. The unactivated zeolite molecular sieve has adsorbedwater molecules. According to the patentee, the combination of theunactivated zeolite and the conventional stabilizer produces a compoundwith allegedly improved stability as compared to a compounds producedwith either of the two stabilizers separately.

Similarly, U.S. Pat. No. 4,338,226 discloses a process for thestabilization of polyvinyl chloride and stabilizer compositions. Thepatent describes admixing sodium aluminosilicate of small particle size(preferably, 0.1 to 20 microns), calcium salts of fatty acids, zincsalts of fatty acids, partial esters of polyols and fatty acids,thioglycolic acid esters of polyols and polyvinyl chloride or copolymerof vinyl chloride. An aluminosilicate that can be used is crystallinesodium zeolite A. The composition is used for molding mixtures.

U.S. Pat. No. 4,371,656 describes a metal substituted zeolite for use asa stabilizer for halogen containing resins. The stabilizer comprises acrystalline aluminosilicate substituted with ions of metallic elementsbelonging to Group II or Group IVA of the Periodic Table for the Group I(M) metal ion contained in the aluminosilicate. The stabilizer also mustcontain 10% by weight or less as M₂O of residual Group I metal ions. Thestabilizer, zeolite A, according to the patentee claims to have a watercontent of 8% by weight or less. This patent also discloses the use oforganic substances to cover the voids of the zeolite particles andprevent moisture reabsorption.

Stabilized chloride containing resins are also described in U.S. Pat.No. 5,004,776. The stabilizer consists essentially of: (a) an overbasedalkaline earth metal carboxylate or phenolate complex; (b) zeolite; (c)calcium hydroxide; and (d) a complex of at least one metal perchlorateselected from the group consisting of sodium, magnesium, calcium, andbarium perchlorates with at least one compound selected from the groupconsisting of polyhydric alcohols and their derivatives. This stabilizerapparently prevents the discoloration and deterioration in physicalproperties of the chlorine containing resin resulting from thermaldegradation when the resin is subject to thermoforming or exposed to ahigh temperature atmosphere for a long period of time.

Stabilizer compositions for use in halogen containing polymer are alsodescribed in U.S. Pat. No. 5,216,058. The stabilizer compositioncomprises hydrotalcite and a molecular sieve zeolite. The molecularsieve zeolite comprises a Group IA or IIA aluminosilicate.

U.S. Pat. No. 5,582,873 discloses an acid scavenger stabilized halogencontaining organic polymer. The patent also describes the method forprocessing such a polymer. The composition comprises a halogencontaining polymer, an zeolite as the acid scavenger and a heatstabilizer selected from the group consisting of mixed metalstabilizers, organtotin stabilizers, lead stabilizers, metal freestabilizers or any combination thereof. The acid scavengers are sodiumzeolites which have a 13 to 25% water content, and a mean particle sizeof about 3 to about 5 microns.

Thus, there currently exists a need for a halogen containing polymercompound having improved process stability. In particular, a need existsfor a stabilizer for a halogen containing compound comprising a modifiedzeolite which maintains the physical properties of the halogencontaining polymer. More particularly, a need exists for a modifiedzeolite stabilizer for use in chlorinated polyvinyl chloride andpolyvinyl chloride compounds. More particularly, there exists a need fora chlorinated polyvinyl chloride compound which has improvedprocessability including excellent heat stability.

SUMMARY OF THE INVENTION

The present invention comprises novel halogen containing compounds withimproved process stability. These compounds are made from a halogencontaining polymer and a modified zeolite. The modified zeolite has asmall particle size, a narrow particle size distribution and a watercontent of less than 10 weight percent. Furthermore, the presentinvention also comprises a method of forming such a compound.

DETAILED DESCRIPTION

As described above, the present invention comprises a composition of ahalogen containing polymer and a modified zeolite, wherein such modifiedzeolite imparts stability to the halogen containing polymer and widensthe range of temperatures which can be used in the processing of suchhalogen containing compounds. When incorporated into the compound, themodified zeolite does not contribute to the deterioration of thephysical properties of the compound.

Examples of possible halogen containing polymers that can be used in theinstant invention include polyvinyl chloride, chlorinated polyvinylchloride, polyvinylidene chloride, polyvinyl bromide, polyvinylfluoride, polyvinylidene fluoride, copolymers of vinyl chloride with acopolymerizable ethylenically unsaturated monomer such asvinylidenechloride, vinyl acetate, vinyl butyrate, vinyl benzoate,diethyl fumarate, diethyl maleate, other alkyl fumarates and maleates,vinyl propionate, methyl acrylate, 2-ethylhexylacrylate, butyl acrylate,ethyl acrylate, and other alkyl acrylates, methyl methacrylate, ethylmethacrylate, butyl methacrylate, hydroxyethyl methacrylate, and otheralkyl methacrylates, methyl alpha-chloracrylates, styrene, vinyl etherssuch as vinyl ethyl ether, vinyl chloroethyl ether, vinyl phenyl ether,vinyl ketones such as vinyl methyl ketone, vinyl phenyl ketone,1-fluoro-1-chloroethylene, acrylonitrile, chloroacrylonitrile,allylidene diacetate, chloroallylidene diacetate, ethylene and propyleneand polymer blends such as blends of polyvinyl chloride andpolyethylene, polyvinyl chloride and chlorinated polyethylene, polyvinylchloride and polybutylmethacrylate and any combinations of theforegoing. The amount of the halogen containing polymer contained in thecompound can range from about 70 to about 99 weight percent. However,the exact amount of the halogen containing polymer used in the compoundis dependent upon its end use and is well within the purview of one ofordinary skill in the art.

Preferably, the halogen containing polymer is either polyvinyl chlorideor chlorinated polyvinyl chloride. Most preferably, the halogencontaining polymer is chlorinated polyvinyl chloride.

The polyvinyl chloride (“PVC”) which can be used in the presentinvention preferably has an inherent viscosity in the range of 0.52 to1.0; a fused density of about 1.35 grams/cubic centimeter and a chlorinecontent of about 56.7%. The PVC resin can be formed by mass, suspensionor emulsion polymerization techniques. Examples of suitable PVC resinswhich can be used to form the halogen containing compounds of theinstant invention include Geon 103EPF76TR, 103 EPF76, 30, 110X440, 27and 1023PF5 PVC; all available from The Geon Company.

The PVC polymers can be homopolymers or copolymers of polyvinylchloride.These polymers generally have a density of about 1.40 grams/cubiccentimeter. Copolymers of PVC are formed predominately with PVC andother copolymers such as for example vinyl acetate. Generally, thesecondary monomer is present in the range of five percent. A furtherdiscussion of PVC copolymers can be found in Volume 1 of Encyclopedia ofPVC, edited by Leonard I. Nass, Marcel Dekker, Inc. (N.Y. 1976, Chap.4).

Alternatively, PVC compounds can also be used. Examples of suitable PVCcompounds include: Geon M6215 and M6230 rigid injection molding PVC;Geon 85890 and 85891 cellular injection molding PVC; Geon 8700A, 8700x,87256, and 87160 interior rigid extrusion PVC; Geon 87416, 87703 and6935 exterior rigid extrusion PVC; and Geon 85893, 87344, 87345, 87538,87695 and 87755 rigid powder extrusion PVC. The various grades of theGeon PVC are commercially available from The Geon Company.

The most preferred halogen containing polymer used in the compound ofthe instant invention is chlorinated polyvinyl chloride. Chlorinatedpolyvinyl chloride (“CPVC”) is known to have excellent high temperatureperformance characteristics, among other desirable physical properties.Typically, CPVC has an excess of 57% bound chlorine. CPVC isconveniently made by the chlorination of a polymer of vinyl chloride(PVC), which include both homopolymers and copolymers of vinyl chloride,having a chlorine content of up to 56.7%.

CPVC is obtained by chlorinating homopolymers or copolymers of PVCcontaining less than fifty percent (50%) by weight of one or morecopolymerizable comonomers. Preferably, comonomers are not used.However, suitable comonomers include acrylic and methacrylic acids;esters of acrylic and methacrylic acid wherein the ester portion hasfrom 1 to 12 carbons; hydroxyalkyl esters of acrylic and methacrylicacid (for example hydroxymethyl methacrylate, hydroxyethyl acrylate,hydroxyethyl methacrylate and the like); glycidyl ester of acrylic andmethacrylic acid (for example glycidyl acrylate, glycidyl methacrylateand the like); alpha,beta-unsaturated dicarboxylic acids and theiranhydrides (for example maleic acid, fumaric acid, itaconic acid and thelike); acrylamide and methacrylamide; acrylonitrile andmethacrylonitrile; maleimides; olefins (for example ethylene, propylene,isobutylene, hexene and the like); vinylidene halide; vinyl esters;vinyl ethers; crosslinking monomers (for example, diallyl phthalate,ethylene glycol dimethacrylate, methylene bis-acrylamide, divinyl ether,allyl silanes and the like).

Any post chlorination processes can be used to form CPVC polymer havingmore than fifty-seven percent (57%) by weight chlorine based upon thetotal weight of the polymer. Preferably, the CPVC polymer has a chlorinecontent in the range of about sixty percent (60%) to about seventy fourpercent (74%) by weight based upon the total weight of the polymer. Thepost chlorination processes which can be used include any commercialprocess or the like such as solution process, fluidized bed process,water slurry process, thermal process or liquid chlorine process or twostep process which comprises post chlorinating the vinyl chloridepolymer in the presence of a peroxy catalyst during both steps. In asmuch as the post chlorination processes are known to the art as well asthe literature, they will not be discussed in detail here. Ratherreference is hereby made to U.S. Pat. Nos. 2,996,049; 3,100,762;4,412,898 3,532,612; 3,506,637; 3,534,013; 3,591,571; 4,049,517;4,350,798; 4,377,459, 5,216,088 and 5,340,880 which are hereby fullyincorporated by reference as to the method of forming CPVC by postchlorinating PVC. The preferred process in forming the CPVC from the PVCis the aqueous suspension process disclosed in U.S. Pat. No. 4,412,898.

In addition, blends of various CPVC resins can also be used. Forexample, the CPVC resin can be blended with PVC homopolymers orcopolymers or with another CPVC resin in an amount of other resin ofabout 1 weight percent to about 50 weight percent. Additionally, theCPVC can also be blended from about 1 weight percent to about 50 weightpercent with another other halogen containing polymer or polymers.

The CPVC used in the invention desirably will have a fused density inthe range of approximately 1.38 to 1.65 grams/cubic centimeter at 25°Centigrade, an inherent viscosity (I.V.) in the range of about 0.52 toabout 1.0 and a chlorine content of at least sixty percent (60%). Thepreferred fused density of the CPVC resin is in the range of about 1.51to about 1.65 grams/cubic centimeter. The preferred inherent viscosityis in the range of about 0.68 to about 0.92. The preferred chlorinecontent of the CPVC is about 63% to about 70.5%. Examples of suitableCPVC resins to use in forming the compound of the instant inventioninclude TempRite® 677×670 CPVC, and TempRite® 674×571 CPVC, allavailable from The B.F. Goodrich Company. TempRite® is a registeredtrademark of The B.F. Goodrich Company. The most preferred CPVC resin isTempRite® 674×571 CPVC resin.

Alternatively, CPVC compounds can be used in the compounds of thecompound of the instant invention. Examples of suitable compounds whichcan be used include the following TempRite® CPVC compounds: 3104, 3210,88038, 3107, 3109, 3114, 88738, 3105, 3214, 88971, 88027, 3219, 3205,3212, 3206, 88023, 88033, 88955, SP220, 88745 and 3207 CPVC compounds.TempRite® is a registered trademark of The B.F. Goodrich Co. The aboveenumerated compounds are all commercially available from The B.F.Goodrich Co. in Cleveland, Ohio. The most preferred CPVC compound usedin the instant invention is TempRite® 3104 CPVC compound.

The halogen containing polymer is stabilized by an effective amount of amodified zeolite. The modified zeolite should have a narrow particlesize distribution, small particle size, and a reduced water content.Preferably, the zeolite should have a mean particle diameter in therange of about 0.25 to about 1.5 microns, a <90% value particle diameter(90% by weight of the particles are of a particle diameter below therange) of about 0.30 to about 3 microns, and a water content of lessthan 10 weight percent.

Zeolites comprise basically of a three dimensional framework of SiO₄ andAlO₄ tetrahedra. The tetrahedra are crosslinked through the sharing ofoxygen atoms so that the ratio of oxygen atoms to the total of thealuminum and silicon atoms it equal to 2. This relationship is expressedas O/(Al+Si)=2. The electrovalence of the tetrahedra containing aluminumand silicon is balanced in the crystal by the inclusion of a cation. Forexample, the cation can be an alkali or alkaline earth metal ion. Thecation can be exchanged for another depending upon the final usage ofthe aluminosilicate zeolite. The spaces between the tetrahedra of thealuminosilicate zeolite are usually occupied by water. Zeolites can beeither natural or synthetic.

The basic formula for all aluminosilicate zeolites is represented asfollows:

M_(2/n)O:[Al₂O₃]_(x):[SiO₂]_(y):[H₂O]_(z)

wherein M represents a metal, n represents the valence of the metal andX and Y and Z vary for each particular aluminosilicate zeolite.Essentially it is believed that any aluminosilicate zeolite can be usedas a stabilizer in the instant invention, provided that the ratio of thesilicon to aluminum in such aluminosilicate zeolite is less than 3.0 andthat the aluminosilicate zeolite can be incorporated into the halogencontaining polymer. Preferably, the zeolite ratio of silicon to aluminumin such aluminosilicate zeolite is less than 1.5. Most preferably, theratio of silicon to aluminum in such aluminosilicate zeolite is about 1.

It is further believed that the following zeolites which can be used inthe instant invention include but are not limited to zeolite A,described in U.S. Pat. No. 2,822,243; zeolite X, described in U.S. Pat.No. 2,822,244; zeolite Y, described in U.S. Pat. No. 3,130,007; zeoliteL, described in Belgian Pat. No. 575,117 zeolite F, described in U.S.Pat. No. 2,996,358; zeolite B, described in U.S. Pat. No. 3,008,803;zeolite M, described in U.S. Pat. No. 2,995,423; zeolite H, described inU.S. Pat. No. 3,010,789; zeolite J, described in U.S. Pat. No.3,011,869; and zeolite W, described in U.S. Pat. No. 3,102,853.

The preferred zeolites include alone or in combination with anotherGroup I metal, hydrated silicates of aluminum incorporating sodium, ofthe type mNa₂O.xAl₂O₃.ySiO₂.zH₂O. These preferred zeolites includezeolites A, X, and Y. The most preferred zeolite is zeolite 4A. Zeolite4A, preferably has the following formula:

M_(2/n)O:[AlO₂]₁₂:[SiO₂]₁₂:[H₂O]₂₇

wherein M is sodium. Any method can be used to form such zeoliteprovided that the mean particle diameter of the zeolite is less than 1.5microns, and <90% value particle diameter of about 0.30 to about 3microns. Furthermore, when modified, this zeolite must have a watercontent of less than 10 weight percent and should provide for improvedprocess stability when incorporated into a compound.

For example, a relatively simple process can be used to prepare thezeolite of the instant invention. First, the zeolite is synthesized. Theexact synthesis will vary dependent upon the specific zeolite beingused; this synthesis is well within the skill of one of ordinary skillin the art. Generally, however, a mixture of the aqueous solution of thematerials which can be represented as mixtures of oxides, Na₂O; Al₂O₃;SiO₂ and H₂O are reacted at a temperature in the range of about 50° C.to about 100° C. for a period of about 45 minutes to about 2000 minutes.Alternatively, the mixture of the reactants are allowed to age fromabout 0.1 to 48 hours at ambient conditions prior to the crystallizationstep. Preferably, the temperature of the reaction is in the range ofabout 50° C. to about 80° C. and the reaction is carried out for about60 to 420 minutes. Most preferably, the temperature is 60° C. to 70° C.with a reaction of time of 90 to 300 minutes. The result of thisreaction is a zeolite having a mean particle diameter in the range ofabout 0.25 to 1.5 microns. The <90 percent particle diameter value is inthe range of about 0.30 to about 3.0 microns.

After the zeolite is formed, it is washed. The zeolite can be washedwith deionized water, filtered and dried at about 100 to about 200° C.,then dehydrated at about 250 to about 500° C. Any means available todehydrate the zeolite can be used. It is believed that the zeolite hasbetter reproductivity if dried. For example, the zeolite can be furnacedehydrated. If furnace dehydrated, any suitable furnace can be usedprovided that the desired temperature can be reached. Generally iffurnace dehydrated, the zeolite is heated to approximately 250 to about500° C. for about 2 to 6 hours. Alternatively, the small particle sizezeolite can be dehydrated in vacuo at approximately 200° C. for about 2to about 6 hours.

These aluminosilicate zeolites are then modified. The modifiedaluminosilicate zeolite has a water content of less than 10 weightpercent. Any method which decreases the water content of thealuminosilicate zeolite can be used. For example, the aluminosilicatezeolite can be modified by chemically altering the surface of thezeolite particles, shock annealing or by a coating or by a combinationof shock annealing and coating processes. The purpose of themodification is to prevent the aluminosilicate zeolite particles fromabsorbing water but still allowing the zeolite particles to react withthe acid released upon the deterioration or degradation of the halogencontaining polymer. If CPVC is the polymer used in the halogencontaining compound, preferably, the water content of the modifiedaluminosilicate zeolite is less than 8 weight percent.

Any organic, inorganic or low molecular weight (<10,000) coating orcoating mixture can be used provided that it has the followingcharacteristics. First, in the case of inorganic coatings, they cannotbe redox active; namely, the composition should have its d shell filled.Second, the coating cannot be water soluble or water permeable. Third,the coating should be reactive or permeable to the halogen acid. Fourth,the coating should not be a Lewis Acid. Preferably the coating used ismiscible with the halogen containing polymer. Examples of suitablecoatings include oxides such as magnesium oxide, paraffin waxes, lowmolecular weight organic matrices such as calcium stearate, highmolecular weight matrices such as siloxanes, acrylic polymers such asmethacrylate polymers. Preferably the coating is either dibutyl tinthioglyocalate or polydimethysiloxane.

The coating can be prepared in situ during the formation of the zeoliteparticles or applied to the zeolite particles in a separate step. Ifapplied in a separate step, care should be taken to ensure the uniformapplication of the coating as well as to avoid clumping. Furthermore,the coating cannot be too thick or too thin, therefore, a balance mustbe obtained so as to ensure low water absorption but retain activity ofthe zeolite particles as acid scavenger.

Alternatively, the zeolite particles can be modified by shock annealingthe particles. With the use of a shock annealing process for the zeoliteparticles, a phase transformation occurs at the outer surface of thezeolite particle shell. It is believed that the phase transformationcauses the collapse of the zeolite structure at the outer surface. Theshock annealing occurs at a temperature above the phase transformationtemperature of the zeolites followed by rapid cooling. The shockannealing is carried out for the appropriate time to cause the outersurface of the particles to collapse. Exposure time to this temperatureabove the phase transformation temperature is however limited tominimize the bulk absorption of thermal energy and to limit the phasetransformation to the outer surface of the particles. The temperature atwhich the zeolite is heated during the shock annealing process isdependent upon the particular zeolite being shock annealed. Thetemperature as well as the time to shock anneal is well within the skillof one of ordinary skill in the art.

One method to shock anneal the zeolite particles is disclosed in thecopending application filed by the instant inventors, entitled “Zeolitesand Method of Making Thereof”, filed concurrently herewith. The contentsof the application are incorporated in its entirety herein.

As described in the copending application, the zeolite particles arethen placed in a furnace during the shock annealing step. Preferably,the particles are placed in a preheated crucible which can be made fromquartz, high temperature steels or aluminum oxide. The crucible with theparticles are returned to a muffle furnace. Any furnace can be used solong as it reaches the desired temperature. In the most preferredembodiment, an aluminum oxide crucible is preheated to approximately 700to 1200° C. prior to the addition of the small particle size zeolite.

Once the zeolite is added, it is heated about 1 to about 30 minutes inthe temperature range of about 700 to about 1200° C. After the zeoliteparticles are heated, as set forth in further detail in the copendingapplication, they are cooled. Any cooling means can be used so long asthe temperature is cooled below the phase transformation temperature ina matter of seconds, for example, about 600° C. for zeolite 4A.Therefore, the particles can be cooled by air, water, carbon dioxide orliquid nitrogen.

Alternatively, the zeolite particles can be modified by both shockannealing and coating. If such a combination method is used to modifythe zeolite particles, they are first shock annealed to within 15 to 10percent of the desired optimum properties and then coated. By using botha coating and the shock annealing step, it may be possible to use othercoatings which do not meet all the listed parameters set forth abovewith respect to the coatings.

The amount of the modified zeolite added to the halogen containingpolymer to form the compounds of the instant invention is generally inthe amount of about 0.5 to about 10 per one hundred parts of halogenresin used in the compound. Most preferably, the amount of modifiedzeolite added to the compound is in the range of about 0.4 to 7 weightpercent of the compound. By adding the zeolite to the compound, thedynamic thermal stability of the compound as measured by ASTM D 2538 isincreased from 10% to 300% compared to a control compound withoutzeolite.

In addition to the halogen containing polymer and the modified zeolitestabilizer, other ingredients typically added to halogen containingpolymers can be included in the compounds of the instant invention. Theamount and nature of these ingredients is dependent upon the end use ofthe halogen containing polymer. The ingredients and their amount can betailored to meet the end-use needs by one of ordinary skill in the art.

For example, other stabilizers can also be used in conjunction with themodified zeolite stabilizer in the halogen containing polymer of theinstant invention depending upon the halogen polymer used. Examples ofpossible stabilizers to use in halogen containing polymers include tinstabilizers, lead stabilizers, as well as stabilizers containinglithium, sodium, potassium, magnesium, calcium, strontium, barium, zinc,cadmium, aluminum, lead and antimony. Many of these enumeratedstabilizers fall into a group of stabilizers called metal soapstabilizers. Metal soap stabilizers are metal carboxylates wherein thecarboxylic acid typically has a chain length of 8 to 18 carbon atoms.Metal soap stabilizers can also include mixed metal soaps stabilizers.Examples of some mixed metal soap stabilizers include barium/cadmium,barium/cadmium/zinc, barium/zinc, barium/tin, barium/lead, cadmium/zinc,calcium/zinc, calcium/zinc/tin, strontium/zinc.

Suitable tin stabilizers include tin salts of monocarboxylic acids suchas stannous maleate. Examples of tin stabilizers include withoutlimitation: alkylstannoic acids, bis(dialkyltin alkylcarboxylate)maleates, dialkyltin bis(alkylmaleates), dialkyltindicrotonates, dialkyltin diolates, dialkyltin laurates, dialkyltinoxides, dialkyltin stearates, alkylchlorotin bis(alkylmercaptides),alkylchlorotin bis (alkylmercaptopropionates), alkylthiostannoic acids,alkyltin tris(alkylmercaptides), alkyltin tris(alkylmercaptoacetates),alkyltin tris(alkylmercaptopropionates),bis[dialkyl(alkoxycarbonylmethylenethio)tin]sulfides, butyltin oxidesulfides, dialkyltin bis(alkylmercaptides), dialkyltinbis(alkylmercaptoacetates), dialkyltin bis(alkylmercaptopropionates),dialkyltin β-mercaptoacetates, dialkyltin β-mercaptoacetates, dialkyltinβ-mercaptopropionates, dialkyltin sulfides, dibutyltin bis(i-octylmaleate), dibutyltin bis(i-octyl thioglycolate), dibutyltinbisthiododecane, dibutyltin β-mercaptopropionate, dimethyltinbis(i-octyl thioglycolate), dioctyltin laurate, methyltin tris(i-octylthioglycolate). Examples of a commercially available tin stabilizer areMark 292 and Mark 1900 stabilizers from Witco Chemical and Thermolite 31stabilizer from Elf Atochem.

Lead stabilizers can also be used in the halogen containing compounds ofthe instant invention. Examples of lead stabilizers are dibasic leadstearate, tribasic lead stearate, dibasic lead phthalate, tribasic leadphosphite, basic lead silico-sulfate, tribasic lead sulfate, tetrabasiclead sulfate and lead carbonate.

Other co-stabilizers may be included in the compounds with thestabilizers if such stabilizers are used in addition to the modifiedzeolite stabilizer, and if desired, but are not necessary. However, if asolid co-stabilizer is added, the particle size of the co-stabilizermust be small enough so as not to affect the impact properties of thecompounds described herein. Examples of co-stabilizers include metalsalts of phosphoric acid, polyols, epoxidized oils, beta-diketones andacid acceptors which are not detrimental to the base halogen containingpolymer used. The stabilizers can be used by themselves or in anycombination as desired. Specific examples of metal salts of phosphoricacid include water-soluble, alkali metal phosphate salts, disodiumhydrogen phosphate, orthophosphates such as mono-,di-, andtri-orthophosphates of said alkali metals, alkali metal polyphosphates,-tetrapolyphosphates and -metaphosphates and the like. Polyols such assugar alcohols, and epoxides such as epoxidized soya oil can be used.Examples of possible acid acceptors include potassium citrate, aluminummagnesium hydroxy carbonate hydrate. An example of commerciallyavailable aluminum magnesium hydroxy carbonate hydrate is Hysafe 510,available from the J.M. Huber Company.

Chlorinated polyethylene (CPE) can also be added to the halogencontaining polymer compound stabilized by the modified zeolite. The CPEis a rubbery material resulting from the chlorination of polyethylenehaving a substantially linear structure. The polyethylene can bechlorinated by various methods including aqueous suspension, solution orgas phase methods. An example of a method for preparing CPE can be foundin U.S. Pat. No. 3,563,974. Preferably, the aqueous suspension method isused to form the CPE. If used as an impact modifier, the CPE materialcontains from 5 to 50% by weight of chlorine. Preferably, the CPEcontains from 25 to 45% by weight of chlorine. However, the CPE cancomprise a mixture of chlorinated polyethylenes, provided that theoverall mixture has a chlorine content in the range of about 25 to 45%by weight chlorine. CPE is commercially available from The DuPont DowElastomer Company. The preferred CPE materials to be used in thecompound include Tyrin 3611P, Tyrin 2000 and Tyrin 3615P; all availablefrom the DuPont Dow Elastomer Company. Tyrin is a trademark of theDuPont Dow Elastomer Company.

The modified zeolite stabilized halogen containing polymer compound mayalso include acrylic impact modifiers. U.S. Pat. No. 3,678,133 describesthe compositions conventionally referred to as acrylic impact modifiers.Generally, the acrylic impact modifier is a composite interpolymercomprising a multi-phase acrylic base material comprising a firstelastomeric phase polymerized from a monomer mix comprising at least 50wt. % alkyl methacrylate having 1-4 carbon atoms in the alkyl group andhaving a molecular weight of from 50,000 to 600,000. Further, the patentstates that the polymerization of the rigid thermoplastic phase ispreferably conducted in such a fashion that substantially all of therigid phase material is formed on or near the surface of the elastomericphase. Acrylic impact modifiers are polyacrylates including (C₄-C₁₂)acrylate homo or copolymers, second stage graft copolymerized withmethyl methacrylate and styrene, poly(ethylhexylacrylate-co-butyl-acrylate) graft copolymerized with styrene, and/oracrylonitrile and/or methyl methacrylate; polybutyl acrylate graftpolymerized with acrylonitrile and styrene. Examples of suitable acrylicimpact modifiers include Paraloid EXL-2330, KM 330, KM 334, and KM 365;all of which are available from Rohm and Haas. Paraloid is a trademarkof the Rohm & Haas Company. Additionally Durastrength 200, availablefrom Elf Atochem, and Kane Ace FM-10 and Kane Ace FM-25, available fromKaneka, are examples of commercially available acrylic impact modifiers.

Methyl butadiene styrene (“MBS”) impact modifiers can also be added tothe compounds of the present invention. MBS polymers are graft polymers.Generally, MBS impact modifiers are prepared by polymerizing methylmethacrylate or mixtures of methyl methacrylate with other monomers inthe presence of polybutadiene or polybutadiene-styrene rubbers. Furtherinformation on MBS impact modifiers can be found in the Second Editionof the Encyclopedia of PVC, edited by Leonard I. Nass, Marcel Dekker,Inc. (N.Y. 1988, pp. 448-452). Examples of commercially available MBSimpact modifiers include Paraloid KM 680, BTA 733, BTA 751, BTA 753available from Rohm & Haas, Kane Ace B-22 impact modifier and Kane AceB-56 impact modifier available from Kaneka.

Other additives can also be added to the halogen containing polymercompounds as needed. Conventional additives known in the art as well anyother additives may be used, provided that the additive does not alterthe physical properties and the process stability associated with thenovel compounds. Examples of additives which can be used includeantioxidants, lubricants, other stabilizers, other impact modifiers,pigments, glass transition enhancing additives, processing aids, fusionaids, fillers, fibrous reinforcing agents and antistatic agents. Theamount and nature of the additives incorporated into the halogencontaining compounds stabilized by the modified zeolite is well withinthe skill of one of ordinary skill in the art.

Exemplary lubricants are polyglycerols of di- and trioleates,polyolefins such as polyethylene, polypropylene and oxidized polyolefinssuch as oxidized polyethylene and high molecular weight paraffin waxes.Since several lubricants can be combined in countless variations, thetotal amount of lubricant can vary from application to application.Optimization of the particular lubricant composition is not within thescope of the present invention and can be determined easily by one ofordinary skill in the art. Preferably, an oxidized polyethylene is used.An example of an oxidized polyethylene is AC 629A, sold by AlliedSignal. In addition to the oxidized polyethylene, preferably a paraffinwax is also included in the compounds of the instant invention. Anexample of a paraffin wax is Paraffin 160F Prill from Witco.

Suitable processing aids include acrylic polymers such as methylacrylate copolymers. Examples of process aids include Paraloid K-120ND,K-120N, K-175; all available from Rohm & Haas. A description of othertypes of processing aids which can be used in the compound can be foundin The Plastics and Rubber Institute: International Conference on PVCProcessing, Apr. 26-28 (1983), Paper No. 17.

An example of antioxidants to be used in the halogen containingcompounds include Irganox 1010(tetrakis[methylene(3,5-di-tert-butyl-4-hydroxy-hydrocinnamate)]methane)sold by Ciba, if used at all.

Suitable pigments include among others titanium dioxide, and carbonblack. Examples of titanium dioxide is Tiona RCL-6 and RCL-4 fromMillenium Inorganics. An example of carbon black is Raven 410, availablefrom Columbian Chemicals.

Suitable inorganic fillers include talc, clay, mica, wollastonite,silicas, and other filling agents.

The components of the unique compound can be made in any manner whereinthe various components are added together and mixed under heat. Forexample, the appropriate amount of the halogenated resin or halogencompound can be added to a vessel such as Henschel mixer or a ribbonblender. The remaining ingredients of the compound can then be addedthereto and mixed until the blend is homogeneous. If pellets are to beformed, the compound can be melt mixed. Melt mixing can generally occurin the temperature range of about 150 to about 250° C., if CPVC is thehalogenated resin used as the base polymer to form the instant compound.Once the blend is formed, it can be processed further depending upon thedesired application in any conventional manner, using extrusion ormolding techniques.

If extrusion techniques are used to process the composition of thepresent invention, generally conventional extrusion machinery such as amultiscrew extruder or a single screw extruder are used. An extrudergenerally has conveying means, an intermediate screw processing meansand a final die through which the material is discharged in the form ofan extrudate. Generally, a multi-screw extruder is used for theextrusion of pipe. Examples of possible conventional extruders to beused to process the CPVC and PVC compounds containing the modifiedzeolite include the following twin screw counterrotating extruder modelsfrom Cincinnati Milacron: CM 35HP, CM 55HP, CM 65HP, CM 80HP, CM 92HP.Examples of suitable conical twin screw extruders from Krauss Maffeiinclude KMD-2/40KK and KMD-2/50KK.

If the halogen containing polymer compound contains CPVC and is madeaccording to the instant invention, it has the followingcharacteristics: a tensile strength in the range of about 5,000 to about10,000 psi (as measured according to ASTM D 638-95); a Notched Izod inthe range of about 1.0 to about 20 ft.lb. per inch of notch (as measuredaccording to ASTM D 256-93A); a dynamic thermal stability in the rangeof about 20 to about 60 minutes as measured by ASTM D 2538); a heatdistortion temperature in the range of about 80 to about 140° C. (asmeasured by ASTM D 648-95). Generally, the compound containing themodified zeolite maintains approximately 90% of its physical propertiesas compared to the same compound without the modified zeolite. Thisnovel compound can be formed into any article desired. Examples includebut are not limited to sheet, pipe, ducts, fittings, valves, injectionmolded and thermoformed industrial parts, appliance housing, fabricatedparts, and different containers.

The following non-limiting examples serve to further illustrate thepresent invention in greater detail.

EXAMPLE I

A zeolite 4A powder was synthesized by individually preparing thefollowing solutions: a sodium silicate solution, a sodium aluminatesolution and a sodium hydroxide solution. The sodium silicate solutionwas prepared by dissolving 255.6 grams of Na₂SiO₃.9H₂O in 650 grams ofwater. The sodium aluminate solution was prepared by dissolving 270.0grams of NaAlO₂ in 320 grams of water and the sodium hydroxide solutionwas prepared by adding 500 grams of NaOH in 650 grams of water. Anadditional solution of 10.0 grams of ZnCl₂ and 90.0 grams of water wasalso prepared. All solutions were maintained at about 55° C. after allsolids are dissolved. The sodium hydroxide solution was then added withstirring to the sodium aluminate solution. The resulting sodiumaluminate/sodium hydroxide solution was added concurrently with the zincchloride solution to the sodium silicate solution, again with stirring.The reaction temperature was maintained at 60° C. for 2 hours and thenfiltered and rinsed. A zeolite 4A produced by this method exhibited thefollowing properties.

The particle size of the zeolite powder as determined using a Coulter LSParticle Size Analyzer was as follows: a mean particle diameter of 0.9μm and <90% value of 1.8 μm.

A sample dehydrated at 350° C. exhibited a weight gain of 22% after 2days of exposure to ambient conditions. In contrast, most commerciallyavailable zeolites will exhibit a moisture gain of about 18 to about 22weight % within 48 hours.

The Dynamic Thermal Stability (DTS) measured according to ASTM D 2538 ofa TempRite® 3104 CPVC compound (commercially available from The B.F.Goodrich Company) was evaluated with and without the above zeolite usinga Brabender torque rheometer set at a 208° C. bowl temperature, 35 rpmand a 70 gram loading. The DTS time of the TempRite® 3104 CPVC controlwas 13 minutes and with the addition of 3 parts per hundred resin (phr)of the zeolite 4A prepared according to Example I to the TempRite® 3104CPVC compound, the DTS time was increased to 36 minutes, a 157% increaseover the control value. The DTS increase is defined as(DTS_(zeolite containing)−DTS_(control (no zeolite))/DTS_(control)×100%).A longer DTS time is indicative of a compound with enhanced stability.

EXAMPLE II

A 20.0 gram portion of a dehydrated zeolite prepared according toExample I was calcined by gradually heating to 840° C. for one (1) hourand cooled to room temperature gradually under vacuum. The resultingmaterial exhibited virtually no weight gain due to water uptake uponexposure to ambient conditions for 500 hours. The DTS time of theTempRite® 3104 CPVC was unchanged upon addition of 3 phr of the calcinedzeolite (0% increase over control DTS value, indicating that the zeolitehas lost its reactivity under those calcination conditions).

EXAMPLE III

An 100 mL Al₂O₃ crucible was heated to 840° C. in a muffle furnace. Thecrucible was extracted from the furnace and a 20.0 gram portion of adehydrated zeolite prepared according to Example I was added to thecrucible which was then returned to the furnace and heated for 15minutes. The heated zeolite powder was then poured into another crucibleat room temperature immediately after removal from the furnace. Theresulting material exhibited 0.7% weight gain due to water uptake uponexposure to ambient conditions after 48 hours. The DTS time of theTempRite® 3104 control was increased upon addition of 3 phr of theshock-annealed zeolite from 13 minutes to 30 minutes (131% increase overcontrol DTS value).

EXAMPLES IV-XX

Another zeolite 4A powder was synthesized by individually preparing thefollowing solutions: (1) a sodium silicate solution; (2) a sodiumaluminate solution; and (3) and a sodium hydroxide solution. The sodiumsilicate solution was prepared by dissolving 255.6 grams of Na₂SiO₃.9H₂O and 10 grams of C₁₁H₂₃COOH in 650 grams of water. The sodiumaluminate solution was prepared by dissolving 270.0 grams of NaAlO₂ in320 grams of water and the sodium hydroxide solution was prepared byadding 500 grams of NaOH in 650 grams of water. An additional solutionof 10.0 grams of ZnCl₂ and 90.0 grams of water was also prepared. Allsolutions were maintained at about 55° C. after all solids weredissolved. The sodium hydroxide solution was then added with stirring tothe sodium aluminate solution. The resulting sodium aluminate/sodiumhydroxide solution was added concurrently with the zinc chloridesolution to the sodium silicate solution, again with stirring. Thereaction temperature was maintained at about 60° C. for 2 hours and thenfiltered and rinsed.

A 100 ml Al₂O₃ crucible was heated to 840° C. in a muffle furnace. Thecrucible was extracted from the furnace and a 20.0 gram portion of adehydrated zeolite prepared according to Example I was added to thecrucible which was then returned to the furnace and heated for 15minutes. The heated zeolite powder was the poured into a stainless steelcup cooled with dry ice immediately after removal from the furnace. Theresulting material exhibited 0.4% weight gain due to water uptake uponexposure to ambient conditions after 48 hours. The DTS time of theTempRite® 3104 control was increased upon addition of 3 phr of theshock-annealed zeolite from 14 minutes to 29 minutes (107% increase overcontrol DTS value). Similarly prepared zeolites were shock-annealedaccording to the parameters tabulated below in Table I:

TABLE I % Temperature Time H₂O DTS Increase Example Coolant (° C.) (min)Uptake (%) (min) in DTS 4 air 840 15 0.8 30.5 118% 5 air 840 15 1.0 33.6140% 6 air 790 20 1.1 28.0 100% 7 air 830 15 1.1 33.4 139% 8 air 785 201.2 30.5 118% 9 air 810 15 1.5 33.3 138% 10 CO_(2(s)) 840 15 0.4 29.4110% 11 CO_(2(s)) 820 15 0.8 33.6 140% 12 CO_(2(s)) 830 15 0.9 33.0 136%13 CO_(2(s)) 810 15 1.1 31.9 128% 14 CO_(2(s)) 820 15 1.5 34.0 143% 15CO_(2(s)) 800 15 3.9 31.4 124% 16 CO_(2(s)) 840 10 4.4 33.3 138% 17CO_(2(s)) 790 15 5.7 32.5 132% 18 CO_(2(s)) 820 10 6.7 31.0 121% 19CO_(2(s)) 750 15 8.0 34.0 143% 20 CO_(2(s)) 770 15 10.5 34.5 146% The(s) subscript in the table with CO₂ indicates that the carbon dioxidewas solid. The examples show that a balance of activity (DTS) and % H₂Ouptake can be achieved with various conditions (temperature, time,cooling conditions).

EXAMPLES XXI-XXXII

Another series of zeolite 4A powders were synthesized by individuallypreparing the following solutions: (1) a sodium silicate solution, (2) asodium aluminate solution; and (3) a sodium hydroxide solution. Thesodium silicate solution was prepared by dissolving 255.6 grams ofNa₂SiO₃. 9H₂O in 650 grams of water. The sodium aluminate solution wasprepared by dissolving 270.0 grams of Na₂AlO₃ in 320 grams of water, andthe sodium hydroxide solution was prepared by adding 500 grams of NaOHin 650 grams of water. All solutions were maintained at about 55° C.after all the solids were dissolved. An additional solution of 10.0grams of ZnCl₂ and 90.0 grams of water was also prepared and used asshown in the table below. 10 grams of C₁₁H₂₃COOH was also added to thesodium silicate solution as also shown in the table below. The sodiumhydroxide solution was then added with stirring to the sodium aluminatesolution. The resulting sodium aluminate/sodium hydroxide solution wasadded concurrently with the zinc chloride solution (when used) to thesodium silicate solution, again with stirring. The reaction temperaturewas maintained at 60° C. for 2 hours and then filtered and rinsed.

A 100 mL Al₂O₃ crucible was heated to 840° C. in a muffle furnace. Thecrucible was extracted from the furnace and a 20.0 gram portion of adehydrated zeolite prepared accordingly was added to the crucible whichwas then returned to the furnace and heated for 15 minutes. The heatedzeolite powder was then poured into a Al₂O₃ crucible at room temperatureand cooled immediately after removal from the furnace. The resultingmaterial exhibited the weight gain tabulated below due to water uptakeupon exposure to ambient conditions after 48 hours. The DTS time of theTempRite® 3104 CPVC control was increased upon addition to 3 phr of therespective zeolite from 14 minutes to the value also tabulated below inTable II:

TABLE II Particle Size mean median % % H₂O ZnCl₂ C₁₁H₂₃COOH Shock-diameter diameter <90% DTS Increase in uptake Example # added addedAnnealed (μm) (μm) (μm) min. DTS (@ 48 hrs.) 21 yes yes yes 1.4 1.1 2.928 100% 0.6% 22 yes yes no 1.7 1.2 2.5 38 171% 12.3%  23 yes no yes 1.51.1 2.6 27  93% 1.0% 24 yes no no 1.4 1.1 2.5 35 150% 14.1%  25 no yesyes 2.1 1.4 5.6 25  79% 0.5% 26 no yes no 1.9 1.6 4.1 32 129% 10.9%  27no no yes 11.8 6.9 5.6 27  93% 0.8% 28 no no no 27.3 14.9 91.9 30 114%2.1% 29 yes yes yes 1.4 1.1 2.2 27  93% 1.0% 30 no no no 1.9 1.5 4.7 31121% 12.0%  31 commercial commercial yes 4.3 4.0 7.1 22  57% 2.8%zeolite zeolite 32 commercial commercial no 3.9 3.6 6.5 34 143% 16.2% zeolite zeolite

This series of experiments was designed to examine the effects of ZnCl₂,C₁₁H₂₃COOH and shock-annealing on particle size distribution to balancethe zeolite reactivity and H₂O uptake as well as the impact of failingto shock anneal on the Dynamic Thermal Stability of the compound. Thecommercial zeolite used in these examples was molecular sieve zeolite4A, having a mean particle size of less than 5 microns, available fromAldrich and bearing product number 23,366-8 (lot #03024-JQ). In Example#28, a zeolite was not formed under the noted conditions.

EXAMPLE XXXIII

Another zeolite 4A powder was synthesized by individually preparing thefollowing solutions: sodium silicate, sodium aluminate and sodiumhydroxide solutions. The sodium silicate solution was prepared bydissolving 195 g of Na₂SiO₃. 5H₂O and 1.5 g. of sodium lauryl sulfate in525 g. of water. The sodium aluminate solution was prepared bydissolving 115 g. of NaAlO₂ and 415 g. of water wherein a solution ofNaOH is added comprising 210 g. of NaOH in 420 g. of water. Theresulting sodium aluminate/sodium hydroxide solution was added to thesodium silicate solution while stirring at room temperature. A thick gelwas instantaneously formed. Agitation was continued for a couple ofminutes until a consistent mixture was obtained. The system was aged forabout 16 hours at room temperature. After this period of aging, theagitation was started again and the system was brought to 60° C. Thereaction temperature was maintained for 3 hours. The solution was thenfiltered and rinsed.

The zeolite 4A powder (as confirmed by X-ray diffraction) has a meanparticle diameter of 0.35 μm and <90% value of 0.50 μm as determinedusing a Coulter LS Particle Size Analyzer.

A sample dehydrated at 350° C. exhibited a weight gain of 22% after 4days of exposure at ambient conditions. The dynamic thermal stability(DTS) measured according to ASTM D 2532 in a TempRite® 3104 CPVCcompound (commercially available from The B.F. Goodrich Company) wasevaluated with and without the above zeolite 4A, using a Brabendertorque rheometer set at 208° C. bowl temperature, 35 rpm and a 70 g.loading. The DTS time of the TempRite® 3104 CPVC control was 20 minutes.With the addition of 3 parts per hundred resin (phr) of the zeolite 4Aprepared according to this example, to the TempRite® 3104 compound, theDTS time was increased to 35 minutes, illustrating an increase of 75% inthermal stability.

EXAMPLE XXXIV

A commercial zeolite 4A powder (Aldrich product #23,366-8, (lot #03024JQ)) has the following particle size distribution as determined using aCoulter LS Particle Size Analyzer: a mean particle diameter of 2.5 μm, amedian particle diameter of 2.4 μm and a <90% value of 4.6 μm. A sampledehydrated at 350° C. exhibited a weight gain of 21% after 2 days ofexposure to ambient conditions.

A 100 mL Al₂O₃ crucible was heated to 840° C. in a muffle furnace. Thecrucible was extracted from the furnace and a 20.0 gram portion of thedehydrated commercial zeolite described above was added to the crucible,which was then returned to the furnace and heated for 15 minutes. Theheated zeolite powder was then poured into another crucible at roomtemperature immediately after removal from the furnace. The resultingmaterial exhibited 1.0% weight gain due to water uptake upon exposure toambient conditions after 48 hours. The DTS time of the TempRite® 3104CPVC control was increased upon addition of 3 phr of the shock-annealedzeolite from 16 minutes to 31.5 minutes (97% increase in DTS).

EXAMPLE XXXV

A commercial zeolite 4A powder (Aldrich product #23,366-8, (lot#03024JQ)) has the following particle size distribution as determinedusing a Coulter LS Particle Size Analyzer: a mean particle size of 2.5μm, a median particle size of 2.4 μm and a <90% value of 4.6 μm. Asample dehydrated at 350° C. exhibited a weight gain of 21% after 2 daysof exposure to ambient conditions.

A 100 mL Al₂O₃ crucible was heated to 820° C. in a muffle furnace. Thecrucible was extracted from the furnace and a 20.0 gram portion of adehydrated commercial zeolite described above was added to the crucible,which was then returned to the furnace and heated for 15 minutes. Theheated zeolite powder was then poured into a stainless steel cup cooledwith dry ice immediately after removal from the furnace. The resultingmaterial exhibited 3.2% weight gain due to water uptake upon exposure toambient conditions after 48 hours. The DTS time of the TempRite® 3104CPVC control was increased upon addition of 3 phr of the shock-annealedzeolite from 13 minutes to 25 minutes (92% increase in DTS).

EXAMPLE XXXVI

TempRite® 3210 CPVC compound (available from The B.F. Goodrich Co.) wasinjection molded using various zeolites as heat stabilizers.

The zeolite 4A used in this experiment was synthesized in the laboratoryas described previously in Example IV. The zeolite 13X was synthesizedin the laboratory as described in U.S. Pat. No. 3,808,321 with thefollowing initial reactant ratios: H₂O/Na₂O=37.4, Na₂O/SiO₂=1.3,SiO₂/Al₂03=3. The zeolite 13×powder produced (as determined by X-raydiffraction) has a mean particle size of 1.5 μm and <90% value of 2.1 μmas determined using a Coulter LS Particle Size Analyzer. Both zeoliteswere dried in a furnace at 450° C. for 24 hours prior to compounding.The ingredients were combined into a Banbury mixer until the melt mixtemperature reached 385° F., then the mixture was rolled into sheetsbefore cubing. Bars were injection molded at 430° F. for various testing(tensile, impact and heat distortion). The physical properties as wellas a description of the chemical composition and particle size of thezeolites are summarized in Table III.

The Congo Red Test was measured in accordance with DIN Standard 53381,Part 1. The Notched Izod was measured according to ASTM D 256-93A, thedrop impact, and the vice crush according to ASTM F 441, the tensiletests according to ASTM D 638-95 and the heat distortion temperature(HDT) according to ASTM D 648-95.

TABLE III Compound No. 1a 1b 1c Control- TempRite ® 3210 TempRite ® 3210TempRite ® 3210 CPVC with CPVC with Description Compound Zeolite 13Xadded Zeolite 4A added Amount of zeolite added 0.0 1.5 1.5 (phr) Meanparticle diameter — 1.5 1.7 (in microns) DTS @ 215 deg C. (min) 10 21 20Congo Red test (min) 35 52 56 Heat Distortion 104 105 104 Temperature(deg C.) Notched Izod 2.9 ± 0.2 2.0 ± 0.4 2.7 ± 0.2 (ft. lb./in.)Tensile Strength (psi) 8320 8370 8560 Tensile Modulus (Kpsi) 340 362 368Tensile Elongation (%) 15 12 21

This experiment illustrates that the use of a small particle sizezeolite with reduced water content increases the thermal stability of aCPVC compound while retaining good physical properties such as impact,tensile and HDT.

EXAMPLE XXXVII

A similar experiment was carried out on a commercial high heat CPVCcompound, TempRite® 3214 CPVC where a small particle size zeolite 4Acontaining 8 wt. % of water was used at 2 phr. The zeolite 4A propertiesused for the run are described in the following Table IV (particle sizeand moisture content). The zeolite 4A was synthesized as described inExample XXIII and was shock annealed at 740° C. for 15 min. in exactlythe same manner as described above. Bars were injection molded at 460°F. and physical properties of the molded samples recorded in Table IV.

TABLE IV Compound Control Compound 1 Zeolite Concentration (phr)  0 2<90% Particle diameter (μm) — 0.7 Mean particle diameter (μm) —  0.47H₂O Content (%) — 8.5 Notched Izod (ft. lb/in)  2.2 ± 0.2  1.6 ± 0.1Tensile Strength (psi) 8590 ± 69  8700 ± 43  Tensile Modulus (Kpsi) 396± 13 407 ± 11 Tensile Elongation (%) 13 13 HDT (° C.) 111 ± 2  114 ± 3 

This example shows that a CPVC compound containing a small particle sizezeolite with 8 wt. % moisture content will exhibit poor physicalproperties due to the outgassing during processing.

EXAMPLE XXXVIII

Another experiment was carried out on a commercial high heat CPVCcompound, TempRite® 3214 CPVC where zeolite 4A was used at variousconcentrations. The zeolite 4A characteristics used for each run aredescribed in the following table (particle size and moisture content).The zeolites in runs 2b through 2d were synthesized as described inExample IV and were shock annealed at 840° C. for 15 min. Agglomerationof the individual particle appears after annealing as indicated by theparticles size distribution in Table V. Run 2e contains a commercialzeolite 4A from Aldrich which was not dried. Bars were injection moldedat 460° F. as described above and physical properties of the moldedsamples recorded.

TABLE V Compound 2a 2b 2c 2d 2e Zeolite 0 1.5 1.5 3 1.5 Concentration(phr) <90% Particle — 3.2 3.2   3.2 5.7 diameter (μm) Mean particlediameter (μm) — 1.2 1   1 3.2 Comments — Aggre- gates Aggregates Aggre-at 4 to 8 at 4 to 10 gates Does not μm μm at 4 μm Aggregate H₂O Content(%) 0.5 0.5 0.5 18% Notched Izod 1.8 1.2 1.2 0.9 0.8 (ft.lb/in) TensileStrength 8640 8800 8940 8960 8950 (psi) Tensile Modulus  408  416  426 427  409 (Kpsi) Tensile 15 12.7 11.2  12 15   Elongation (%) HDT (° C.)117 ± 0 119 ± 0 118.5 ± 5 120 ± 0 117.5 ± 5 Congo Red Test 21.5 40.135.4 57.7 43.7 (min.) Visual surface Appearance (3/4″ burned good goodgood moisture coupling)

This example shows that a CPVC compound containing a large particle sizezeolite with no moisture content will exhibit better thermal stabilityand processing as compared to the control but poor physical properties.

EXAMPLE XXXIX

Physical properties were measured on commercial CPVC compound TempRite®3107 CPVC with the addition of zeolite 4A synthesized as described inExample XXXIII. The zeolite samples were dried at 450° C. for 24 hours.The zeolite was coated with either 33 wt. % butyl tin stabilizer (Mark292, available from Witco Chemical) or 37.5 wt % of polydimethylsiloxaneoil, (SF100, available from GE Plastics) under high shear mixing at roomtemperature. The polymeric coating was applied to prevent waterreabsorption. The compounds were mixed on a Henschel Mixer at 3600 rpmfor 15 min. at 200° F., then rolled into sheets at 400° F. beforeplaques were pressed. Bars were cut to measured physical properties asset forth in Table VI.

TABLE VI Control 1 2 3 TempRite ® 3107 100 100 100 100 CPVC (phr) Amountof zeolite  0  2  2  2 added (phr) <90% Zeolite — 0.6 0.6 0.6 particlediameter (μm) Zeolite mean — 0.4 0.4 0.4 particle diameter (μm) Coating— Mark 292 SF100 None 33 wt. % 37 wt. % % H₂O in Zeolite — 1.8 1.8 0  Notched Izod 9.5 ± 9.6 ± 10.5 ± 10.2 ± (ft. lb/in) 0.8 0.9 0.2 0.5Tensile Strength 7720 ± 7430 ± 6650 ± 7510 ± (psi) 52 18 177 62 Tensilemodulus  335 ±  355 ±  337 ±  338 ± (Kpsi) 21 21 17 10 Tensile 5.2 ± 4.7± 4.7 ± 5.1 ± Elongation (%) 0.2 0.1 0.1 0.2 HDT (° C.) 102    100   108    108   

This example shows that a CPVC compound containing a small particlezeolite with reduced moisture content will retain good physicalproperties as compared to the control.

EXAMPLE XXXX

Notched Izod Impact and thermal stability were measured on commercialCPVC compound 3107 with the addition of a zeolite 4A, synthesized asdescribed in Example XXXIII, or in the alternative, commerciallyavailable zeolite from Aldrich. The zeolite samples were dried at 450°C. for 24 hours. Bars were cut to measure impact properties. The resultsare summarized in the Table VII.

TABLE VII Control 1 2 3 4 5 TempRite ® 3107 CPVC 100 100 100 100 100 100(phr) Amount of zeolite added  0  2  2  2  2  2 (phr) <90% Zeoliteparticle — 0.6 0.6 4.6 4.6 4.6 diameter (μm) Zeolite mean particle — 0.40.4 2.5 2.5 2.5 diameter (μm) Coating — Mark None None SF100 Mark 292 33wt % 292 33 33 wt % wt % % H₂O in Zeolite — 1.8 0 18 2.4 2.4 NotchedIzod (ft.lb.in) 6.9 ± 7.4 ± 7.3 ± 2.5 ± 2.7 ± 2.1 ± 0.9 0.5 0.5 0.2 0.10.1 DTS (% Increase of Control) — 55% 55% 55% 95% 66%

The DTS increase in Table VII and the application is defined as(DTS_(zeolite containing)−DTS_(control (no zeolite))/DTS_(control)×100%

This example shows that a small particle size zeolite with reducedmoisture content is necessary to achieve improved thermal stabilizationthan while retaining good impact properties in CPVC.

EXAMPLE XXXXI

Two compounds using Geon 103EPF76 PVC resin from The Geon Company weremade in the following manner. The ingredients were mixed in a Farrelintensive mixer, removed at 330° F. and worked on the KSBI 10′×20′ millwith the front roller set at 420° F. and the back roller set at 400° F.Plaques were then cut out of the worked material and compression moldedto ¼ in thickness. Bars were then cut from the plaques for Notched Izodaccording to ASTM D 256-93A. The remaining compound was cubed and strips(3 inch wide and 0.035 inches thick) were extruded using a Brabender ¾inches diameter single screw extruder at 195° C. Variable Height ImpactTesting (VHIT) was measured on the strips according to ASTM D 4226. Acommercial zeolite from Aldrich was used in this case and had a largeparticle size (as described in the Table VIII) and was shock annealed at800° C. for 1 hour to prevent any water adsorption.

The following recipe was used:

PVC 103EPF76 100 phr Dibutyl tin bis-(2ethylhexylmercapto acetate) 2Titanium dioxide 6 Calcium stearate 1 Acrylic processing aid 1.5 Impactmodifier 6 Shock annealed commercial zeolite 4

TABLE VIII Control Compound 1 Zeolite content 0 4 <90% Zeolite — 5.7Particle diameter (μm) Mean Particle — 3.2 diameter (μm) H₂O content (%)— 0 Izod impact 2.6 ± 0.1 1.8 ± 0.4 (ft.lb./in.) VHIT impact 2.1 ± 0.11.85 ± 0.1  (in.lb./in.)

This example illustrates that a commercially available zeolite withreduced water content yields poorer Izod impact and VHIT impact valuesin a PVC compound as compared to the control.

EXAMPLE XXXXII

Two compounds using PVC 103EPF76 resin from The Geon Company were madein the following manner. The ingredients were mixed in an Henschel mixerat 3600 rpm for 15 min. Strips (2 inches wide and 0.035 inches thick)were extruded at 200° C. via a Haake conical twin screw extruder at 200°C. The zeolite used in this case was prepared as described in ExampleXXXIII and dried in a furnace at 450° C. before use. Its characteristicsare summarized in the following table. Variable Height Impact Test(VHIT) values were measured on the strips to quantify impact properties(ASTM D 4226). The following recipe was used:

PVC 103EPF76 100 phr Dibutyl tin bis-(2ethylhexylmercapto acetate) 1.6Titanium dioxide 1 Calcium stearate 1.5 Paraffin wax 1.5 Oxidizedpolyethylene 0.1 Acrylic processing aid 1.0 Impact modifier 5

The following results were obtained:

TABLE IX Control Compound 1 Zeolite content 0 2 <90% Zeolite Particlediameter (μm) — 0.6 Mean Particle diameter (μm) — 0.35 H₂O content (%) —0 VHIT values (in.lb./in.) 2.43 ± 0.18 2.45 ± 0.13

This example illustrates that a small particle size zeolite with reducedwater content yields good impact properties as illustrated by the VHITvalues of the PVC strips.

EXAMPLE XXXXIII

3 phr of a commercial zeolite 4A powder (as received, Aldrich #23,366-8,lot #03024-JQ) was added to a commercial CPVC compound (TempRite® 3104CPVC). The zeolite had the following particle size distribution: a meanparticle diameter of 2.5 μm, a median particle diameter of 2.4 μm and a<90% value of 4.6 μm using a Coulter LS Particle Size Analyzer. The samesample dehydrated at 350° C. exhibited a weight gain of 21% after 2 daysof exposure to ambient conditions. The DTS time of the TempRite® 3104CPVC control was increased upon addition of 3 phr of the commercialzeolite from 13 minutes to 33 minutes (154% increase in DTS). However,staircase drop impact at 22.8° C. dropped 52% (control: 25 ft.lbs. vs.compound with zeolite 4A: 12 ft.lb.) and hoop stress at 82.2° C. dropped16% (control: 4900 psi vs. compound with zeolite 4A: 4120 psi) asmeasured on extruded ¾ inch SDR 11 pipe prepared from TempRite® 3104CPVC.

EXAMPLE XXXXIV

3 phr of a shock-annealed commercial zeolite 4A powder (Aldrich zeolite4A, shock-annealed at 840° C. for 15 minutes) was added to a commercialCPVC compound (TempRite® 3104 CPVC). The particle size distribution ofthe shock-annealed zeolite was determined as follows: a mean particlediameter of 3.1 μm, a median particle diameter of 3.1 μm and a <90%value of 5.7 μm using a Coulter LS Particle Size Analyzer. Theshock-annealed sample exhibited a weight gain due to water uptake of <2%after 2 days of exposure to ambient conditions. The DTS time of theTempRite® 3104 CPVC control was increased from 16 minutes to 33 minutes(106% increase in DTS). However, the staircase drop impact at 22.8° C.dropped 44% (control: 25 ft.lb. vs. compound with shock-annealedzeolite: 14 ft.lb.) and hoop stress at 82.2° C. dropped 9% (control:4900 psi vs. compound with shock-annealed zeolite: 4460 psi) as measuredon extruded ¾ inch SDR 11 pipe prepared from TempRite® 3104 CPVC.

EXAMPLE XXXXV

Polyvinyl chloride was mixed with various additives to prepare a sidingcompound, using the following formulation (in parts by weight)in TableX:

TABLE X Material Manufacturer Parts PVC resin (IV = 0.92, Geon Co. 100.0Geon 130 EPF 76-TR) Calcium stearate Witco 1.3 Paraffin wax Witco 1.0Oxidized polyethylene, Allied Signal 0.1 AC 629 Acrylic process aid,Rohm & Haas 1.25 Paraloid K-120ND Acrylic toughener Rohm & Haas 6.0Titanium dioxide, Tioxide 10.0 Tioxide RFC-6 Methyl (thioglycolato)Witco 0.5 or 1.5 tin (IV)-based stabilizer, Mark 1900 Shock-annealedzeolite Example IV 0.0, 2.0 or 4.0

The zeolite was synthesized and shock-annealed as outlined in ExampleIV. The formulation was well mixed and charged to a torque rheometerand, run at the following conditions (ASTM D 2532) set forth in TableXI:

TABLE XI Bowl setting (temperature) 170° C. Rotor rate (RPM)  60 Preheattime  3 min. (at 5-10 rpm) Compound loading  67 grams

The formulation was continuously mixed at high temperature untildegradation occurred, as evidenced by a substantial change in torque.Results in Table XII show that the addition of the shock-annealedzeolite considerably enhanced the stability time observed for the PVCcapstock/unitary construction siding formulation.

TABLE XII Shock- Tin annealed DTS Rotor stabilizer zeolite time % DTScondi- Example (parts) (parts) (min.) Increase tions A 0.5 0.0 14  0%Clean B 0.5 2.0 24 71% Clean C 0.5 4.0 29 107%  Clean D 1.5 0.0 29  0%Clean E 1.5 2.0 43 48% Clean F 1.5 4.0 60 107%  Clean

EXAMPLE XXXXVI

Polyvinyl chloride was mixed with various additives to prepare a pipefittings compound, using the following formulation (in parts byweight)in Table XIII:

TABLE XIII Material Manufacturer Parts PVC resin Geon Co. 100.0 (IV =0.72) Calcium stearate Witco 0.8 Paraffin wax Witco 0.8 Oxidizedpolyethylene Allied Signal 0.1 Acrylic process aid Rohm & Haas 1.0 MBStoughener Rohm & Haas 5.0 Titanium dioxide Tioxide 1.0 Calcium carbonatePfizer 3.0 Methyl (thioglycolato) Witco 0.5 or 1.0 tin(IV) -basedstabilizer Shock-annealed Example IV 0.0, 2.0 or 4.0 zeolite (ExampleIV)

The zeolite was synthesized and shock-annealed as described in ExampleIV. The formulation was well mixed and charged to a torque rheometer,run at the following conditions (ASTM D 2532) in Table XIV:

TABLE XIV Bowl setting (temperature) 170° C. Rotor rate (RPM)  60Preheat time  3 min. (at 5-10 rpm) Compound loading  67 grams

The formulation was continuously mixed at high temperature untildegradation occurred, as evidenced by a substantial change in torque.Results in Table XV showed that the addition of the shock-annealedzeolite considerably enhanced the stability time observed for the PVCfitting formulation.

TABLE XV Shock- Tin annealed Stabilizer zeolite DTS time % DTS RotorExample (parts) (parts) (min.) Increase Conditions G 0.5 0.0 17  0%Sticking H 0.5 2.0 20 18% Clean I 0.5 4.0 22 29% Clean J 1.0 0.0 24  0%Sticking K 1.0 2.0 25  4% Clean L 1.0 4.0 31 29% Clean

EXAMPLE XXXXVII

1 inch schedule 40 pipe extrusion was carried out using a CM-55 HP twinscrew extruder with a commercial TempRite® 3104 CPVC compound using 3parts of commercial zeolite from Aldrich which had an average particlediameter of 3.1 μm and a 90% and below value of 5.7 μm. The zeolite wasdried at 450° C. for 24 hours prior to compounding. A counterrotatingintermeshing twin screw extruder, CM55HP, manufactured by CincinnatiMilacron was used to extrude the pipe. The extruder was run at 420° F.with a screw rotation speed of 20 rpm in this Example. The results ofthe physical properties of the extruded sample (pipe properties) are asfollows in Table XVI:

TABLE XVI Control 1 2 TempRite ® 3104 CPVC 100 100 100 Zeolite 4A —  3 3 % DTS increase 118% 118% Staircase Drop Impact at 40 ± 3 11 ± 1 20 ±4 73° F. (ft.lb) Staircase Drop 10 + 1 <6 <6 Impact at 32° F. (ft.lb)Vice Crush passes 3/3 3/3 3/3 Compression 60% full 3/3 2/3 3/3 PipeAppearance Good Very poor Poor (pimples)

In this extrusion run, while the thermal stability is increased by thepresence of the commercial zeolite, it also reduces the staircase dropimpact by 50 to 80% at 73° F. and over 40% at 32° F.; the vice crushtest is substantially equivalent in the absence or presence of thezeolite and the pipe appearance is poorer when the large particles sizezeolite is used (pimples).

EXAMPLE XXXXVIII

Two compounds were formulated using the 69.7% chlorine two-step CPVCResin formed described in U.S. Pat. No. 5,216,088. These resins wereformulated into compounds using the 69.5% chlorine recipe set forth inTable 3 of European Patent Application EP 808851 A2 with the followingmodifications: 69.7% chlorine two-step CPVC resin and 3 parts ofchlorinated polyethylene were used in this Example as well as 0.25 partsof antioxidant along with commercial Linde 13×zeolite which had beenpre-dried for 54 hours at 286° C. followed by cooling under vacuum weremade in the following manner. Zeolite 13×had a average particle size ofabout 5.5 microns and was immediately used to minimize water absorption.The ingredients were mixed in the Farrell intensive mixer, removed at420° C. and worked on the KSBI 10′×20′ mill with the front roller set at430° F. and the back rollers at 420° F. Plaques were then cut out of theworked material and compression molded to ⅛ inch and ¼ inch thicknessusing the following Wabash press conditions:

Pressure setting 50 tons Pressure Temperature 410° C. Low pressure 6minutes High pressure 3 minutes Pre-bump dwell 15 seconds Dwell betweenbumps 5 seconds Bump open time 8 seconds Bump counter 2

Bars were cut from the final plaques for Notched Izod according to ASTMD 256-93A, and tensile strength according to ASTM D 638-94B. The resultsare summarized in Table XVII below:

TABLE XVII Compound with Control Zeolite 13X added 1/4″ Notched Izod,23° C. 1.77 0.72 (ft.lb./in.) 1/8″ Tensile Strength, 7810 7460 23° C.(psi) DTS-210° C. DTS Min. 2330 2330 35 rpm, 82 Torque gm cubes (m-gm)DTS Min. 6.4 12.8 Time (minutes) DTS Temp. 231 233 (° C.)

This example shows that commercially available zeolite that has beendried increases the thermal stability time as evidenced by the longerDTS time but yield poorer Izod impact values as a result of largeparticle size.

In summary, novel and unobvious halogen containing polymer compoundswith a modified zeolite stabilizer have been described. Althoughspecific embodiments and examples have been disclosed herein, it shouldbe borne in mind that these have been provided by way of explanation andillustration and the present invention is not limited thereby. Certainlymodifications which are within the ordinary skill in the art areconsidered to lie within the scope of this invention as defined by thefollowing claims.

We claim:
 1. A halogen containing compound comprising a halogencontaining polymer and a zeolite stabilizer, wherein said zeolite has amean particle diameter in the range of 0.25 to 1.5 microns a <90% valueparticle diameter of about 0.30 to about 3 microns, and a reduced watercontent of less than 10 weight percent.
 2. A halogen containing compoundas claimed in claim 1, wherein said halogen containing polymer is chosenfrom the group consisting essentially of polyvinyl chloride, chlorinatedpolyvinyl chloride, polyvinylidene chloride, polyvinyl bromide,polyvinyl fluoride, polyvinylidene fluoride, copolymers of vinylchloride with a copolymerizable ethylenically unsaturated monomer, vinylacetate, vinyl butyrate, vinyl benzoate, alkyl fumarates and maleates,vinyl propionate, alkyl acrylates, alkyl methacrylates, methylalpha-chloracrylates, styrene, vinyl ethers, vinyl ketones,acrylonitrile, chloroacrylonitrile, allylidene diacetate,chloroallylidene diacetate, ethylene and propylene and any combinationsof the foregoing.
 3. A halogen containing compound as claimed in claim1, wherein said halogen containing polymer is chlorinated polyvinylchloride.
 4. A halogen containing polymer as claimed in claim 1, whereinsaid halogen containing polymer is polyvinyl chloride.
 5. A halogencontaining compound as claimed in claim 1, wherein said zeolite ispresent in an amount from about 0.5 to about 10 parts per hundred ofhalogen containing resin.
 6. A halogen containing polymer as claimed inclaim 2, having a dynamic thermal stability at 220 degrees C. of about10 to about 60 minutes.
 7. A halogen containing polymer as claimed inclaim 2 having a Notched Izod in the range of about 1.0 to about 20(ft.lb/in.).
 8. A halogen containing polymer as claimed in claim 2,having a heat distortion temperature in the range of about 80° C. toabout 140° C. degrees.
 9. A halogen containing polymer as claimed inclaim 2, having tensile strength in the range of about 5,000 to about10,000 psi.
 10. A halogen containing polymer as claimed in claim 1,wherein said modified zeolite is a hydrated silicate of aluminum andsodium.
 11. A halogen containing polymer as claimed in claim 10, whereinsaid reduced water content is due to shock annealing.
 12. A halogencontaining polymer as claimed in claim 10, wherein said reduced watercontent is due to a coating on said modified zeolite.
 13. A halogencontaining polymer as claimed in claim 1, wherein said dynamic thermalstability is increased about 10% to about 300% over a control.
 14. Amethod of forming a stabilized halogen containing compound comprising:mixing a halogen containing resin with a modified zeolite stabilizer,wherein said zeolite has a particle diameter in the range of 0.25 to 1.5microns, a <90% value particle diameter of about 0.30 to about 3microns, and a reduced water content of less than 10 weight percent. 15.A method according to claim 14, wherein said halogen containing polymeris chosen from the group consisting essentially of polyvinyl chloride,chlorinated polyvinyl chloride, polyvinylidene chloride, polyvinylbromide, polyvinyl fluoride, polyvinylidene fluoride, copolymers ofvinyl chloride with a copolymerizable ethylenically unsaturated monomer,vinyl acetate, vinyl butyrate, vinyl benzoate, alkyl fumarates andmaleates, vinyl propionate, alkyl acrylates, alkyl methacrylates, methylalpha-chloracrylates, styrene, vinyl ethers, vinyl ketones,acrylonitrile, chloroacrylonitrile, allylidene diacetate,chloroallylidene diacetate, ethylene and propylene and any combinationsof the foregoing.
 16. A method according to claim 15, wherein saidhalogen containing polymer is chlorinated polyvinyl chloride.
 17. Amethod according to claim 15, wherein said halogen containing polymer ispolyvinyl chloride.
 18. A method according to claim 14, wherein saidmodified zeolite is present in an amount from about 0.5 to about 10parts per hundred of halogen containing resin.
 19. A method according toclaim 16, wherein said halogen containing compound with the modifiedzeolite has a dynamic thermal stability at 220° C. of about 10 to about60 minutes.
 20. A method according to claim 16, wherein said halogencontaining compound with the modified zeolite has a notched izod in therange of about 1.0 to about 20 ft.lb./in.
 21. A method according toclaim 16, wherein said halogen containing compound with the modifiedzeolite has a heat distortion temperature in the range of about 80° C.to about 140° C. degrees.
 22. A method according to claim 16, whereinsaid halogen containing compound with the modified zeolite has a tensilestrength in the range of about 5,000 to about 10,000 psi.
 23. A methodaccording to claim 14, wherein said modified zeolite is a hydratedsilicate of aluminum and sodium.
 24. A method according to claim 14,wherein said modified zeolite is shock annealed.
 25. A method accordingto claim 14, wherein said modified zeolite is coated with an inorganic,organic, or low molecular weight coating in order to prevent water fromentering zeolite.
 26. A method according to claim 25, wherein saidcoating is polymethyl siloxane.
 27. A method according to claim 26,wherein said coating is dibutyl thioglycolate.
 28. A composition asclaimed in claim 1, wherein said zeolite is modified by shock annealingor by coating.
 29. A halogen containing compound as claimed in claim 28,wherein said halogen containing polymer is chosen from the groupconsisting essentially of polyvinyl chloride, chlorinated polyvinylchloride, polyvinylidene chloride, polyvinyl bromide, polyvinylfluoride, polyvinylidene fluoride, copolymers of vinyl chloride with acopolymerizable ethylenically unsaturated monomer, vinyl acetate, vinylbutyrate, vinyl benzoate, alkyl fumarates and maleates, vinylpropionate, alkyl acrylates, alkyl methacrylates, methylalphachloracrylates, styrene, vinyl ethers, vinyl ketones,acrylonitrile, chloroacrylonitrile, allylidene diacetate,chloroallylidene diacetate, ethylene and propylene and any combinationsof the foregoing.
 30. A halogen containing compound as claimed in claim29, wherein said halogen containing polymer is chlorinated polyvinylchloride.
 31. A halogen containing polymer as claimed in claim 29,wherein said halogen containing polymer is polyvinyl chloride.
 32. Ahalogen containing polymer as claimed in claim 29, wherein said modifiedzeolite is present in an amount from about 0.5 to about 10 parts perhundred halogen containing resin.
 33. A halogen containing polymer asclaimed in claim 30, wherein the water content is less than 8 weightpercent.
 34. A method according to claim 14, wherein said zeolite ismodified by shock annealing or by coating.
 35. A method according toclaim 34, wherein said halogen containing polymer is chosen from thegroup consisting essentially of polyvinyl chloride, chlorinatedpolyvinyl chloride, polyvinylidene chloride, polyvinyl bromide,polyvinyl fluoride, polyvinylidene fluoride, copolymers of vinylchloride with a copolymerizable ethylenically unsaturated monomer, vinylacetate, vinyl butyrate, vinyl benzoate, alkyl fumarates and maleates,vinyl propionate, alkyl acrylates, alkyl methacrylates, methylalpha-chloracrylates, styrene, vinyl ethers, vinylketones,acrylonitrile, chloroacrylonitrile, allylidene diacetate,chloroallylidene diacetate, ethylene and propylene and any combinationsof the foregoing.
 36. A method according to claim 35, wherein saidhalogen containing polymer is chlorinated polyvinyl chloride.
 37. Amethod according to claim 35, wherein said halogen containing polymer ispolyvinyl chloride.
 38. A method according to claim 35, wherein saidmodified zeolite is present in an amount from about 0.5 to about 10parts per hundred halogen containing resin.
 39. A method according toclaim 36, wherein the water content is less than 8 weight percent.